Thread-waxing apparatus



S U T M H AP P A 5 A m A D A E R H T Jan. 17, 1956 Filed Nov. 2, 1955 Jan. 17. 1956 F. RASPA THREAD-WAXING APPARATUS Filed Nov. 2, 1953 5 Sheets-Sheet 2 Jan, 17, 1956 IF". RASPA THREAD-WAXING APPARATUS 5 Sheets-Sheet 3 Filed Nov. 2, 1953 THREAD-WAXING APPARATUS Filed Nov. 2. 1953 5 Sheets-Sheet 4 Jan. 17, 1956 F. RASPA THREAD-WAXING APPARATUS 5 Sheets-$heet 5 Filed Nov. 2, 1953 United States Patent THREAD-WAXING APPARATUS Francisco Raspa, Montreal, Quebec, Canada Application November 2, 1953, Serial No. 389,821

12 Claims. (Cl. 112-42) The present invention is concerned with shoe lockstitching machines and, more particularly, stitching machines for lock-stitching all types of shoes.

Machines of this nature are used primarily in the shoe industry wherein a new sole is to be stitched on, and the present invention is directed to improvements in hot wax lock-stitching machines in connection with the automatic waxing of the bobbin threads used.

In machines of this nature, it is of prime importance that the thread used is waxed immediately before it is employed to stitch the shoes. The wax coating on the thread must be hot and must be freshly applied if breakage of the thread is to be avoided. The preferred wax generally used is a hard wax and it cannot be prepared in too large a quantity as, if it is under heat for any length of time, it turns black and becomes brittle. this condition hardens quickly and the thread will become stiff and not lay in the barb of the machine needle as required.

Accordingly, it is general practice in standard machines to provide a supply of hot wax and a relatively small quantity of thread is pre-waxed and is then reeled on the bobbin. The quantity of the thread reeled on the upper bobbin on a standard machine is such that for approximately every two pairs of soles the thread must be replenished. As will be appreciated, this means that the machine must be frequently stopped and fresh wax supplied to a quantity of thread and this thread wound on the upper thread bobbin and so on.

The present invention recognizes these difiiculties and aims to provide a means whereby a greater quantity of thread than usual is made available and provision is also made for supplying wax to the thread so that the entire bobbin can be used without need of replenishing the wax. In accordance with the invention, this is accomplished by providing a relatively small. wax reservoir adjacent to the upper bobbin which is adapted to provide sufiicient wax to the thread for one or two pairs of shoes and means are provided whereby the small wax reservoir is replenished automatically from a larger wax reservoir.

More specifically, and in accordance with the present invention, means are provided on the stitching machine so that the upper thread bobbin is of considerably greater size than is commonly used. This bobbin is placed in a special housing where it is maintained in position by a shuttle driven by a. shuttle driver through an oscillating oem which oscillates the shuttle driver trans-axially so as to rotate the shuttle while still providing a clearance passage between the shuttle and driver for the looping over of the lower thread. The thread on the upper bobbin is threaded through and passes into a small wax reservoir from which it emerges to the needle in the usual manner.

The small wax reservoir contains just suflicient wax to coat enough thread for one or two pairs of soles. An oscillating cam and gear arrangement drives a worm so as to cause a plunger mounted on the upper part of the machine to rise and fall within a wax delivery tube extending into a largewax reservoir mounted above the small Wax in 2,730,975 Patented Jan. 17, 1956 wax reservoir adjacent to the bobbin. With this arrange the withdrawal of a predetermined length of thread, the plunger is automatically actuated to again fill the small reservoir with hot wax. This cycle continues until the thread on the upper bobbin is depleted.

Suitable heating elements are provided adjacent to the large reservoir and the small reservoir so that the wax is kept at the proper temperature for coating as the thread is fed'into the work by the action of the needles.

The main advantage of the present apparatus is that more than the usual amount of thread can be reeled on the upper bobbin and by the feeding of the fresh hot Wax to this thread in small quantities the danger of the wax spoiling and causing breakage of the thread is eliminated. The feeding of the wax, from the large to the small reservoir, is performed automatically so that the machine can be used for a considerably greater length of time than is usual without having to replenish the thread and/or wax. This presents a considerable saving in time and labour on the part of the machine operator.

Having thus generally described the nature of the invention, particular reference will be made to the accompanying drawings wherein there is shown by way of illustration a preferred embodiment of the invention, and in which:

Figure 1 is a view in front elevation of a welting or lock stitch machine wherein there is embodied a thread waxing arrangement in accordance with the invention.

Figure 2 is a view in side elevation ofthe machine construction shown in Figure 1.

Figure 3 is an enlarged detail of the thread-dispensing opening in the bottom of the small reservoir showing the relative position of the thread and the thread-wiping arrangement adapted to evenly coat the thread as it is withdrawn.

Figure 4 is a cross-sectional view of the thread shown in Figure 3 alongthe line 4-4 to illustrate diagrammatically the thread with the exterior hot wax coating.

Figure 5 is an enlarged view of the upper portion of the machine shown in Figure 1 to illustrate the portions of the machine wherein the waxing apparatus in accordance with the present invention is embodied.

Figure 6 is a view in plan of the construction shown in Figure 5.

Figure 7 is an exploded view of the various components making up the main elements of the waxing arrangement in accordance with the present invention. 1

Figure 8 is a sectional view of the upper thread feeder and bobbin holder showing the small wax reservoir and the comparatively large bobbin which fits within the bobbin holder.

Figure 9 is a side elevation of the assembled structure shown in Figure 7 with portions of the machine omitted for clarity.

Figure 10 is a front view of the portion of the machine shown in Figure 9, with the main reservoir and wax feeding cylinder shown in section.

Figure 11 is a view in plan of the section of the machine shown in Figures 9 and 10.

Figure 12 is a diagrammatic view of a portion of the machine shown in Figure 11 along the line 12-12 to illustrate in more detail the cam action rotating the driving gear of the wax feeding piston.

Figure 13 is an enlarged diagrammatic view, partially in section, of the main wax reservoir, the lower wax reservoir and the drive means for the bobbin-containing shuttle.

Figure 14 is a diagrammatic view showing the relative position and movement of the quick-stop arrangement for uncoupling the wax feeding piston drive.

Figures 15, 16, 17 and 18 are diagrammatic views show- 3 ing in step-'by-step sequence the movement of the shuttle and bobbin to illustrate the arrangement whereby the bottom thread is looped over the top thread forming the desired lock stitch.

With particular referenceto'the drawings, the machine illustrated is a standard shoe sewing machine wherein the special apparatus for the maintaining .of the wax in accordand the usualcontrols, including the pressure foot pedal .16, are provided. a I

The lowef' thread used in the stitching process by the machine is fed from a spindle through a waxing tank 32.as is well known in the art. In order that the wax in the tank32 be maintained at the proper temperature the tank is constructed so'as to-provide support for suitable heating elements. This portion of the structure is well known and,'therefore, is not shown in detail. v j

The upper threadis wound on and dispensed from a bobbin usually adjacent the shuttle as is well known in sewing machines of this type and it is in connection with the flwaxin'g and provision of this upper. thread that the present invention is mainly-concerned. V V v Normally, the upper sewing thread is drawnfrom a second spindle of bobbin mounted on the side of the frame of the machine. From the bobbin threadis drawn through the waxing tank and sufficient waxed thread is drawn off from the waxing tank to fill the bobbin. This bobbin winding is usually performed automatically and the bobbin is then placed in the bobbin case so that the machine is'ready for the sewing of approximately one and one-half (l /2) to two (2) pairs of shoe soles. "On depletion of the waxed thread on the bobbin it must be removed from the bobbin case, fresh waxed thread withdrawn from the wax reservoir and wound on, the bobbin replaced and so on.

In accordance withthe present invention, the usual bobbin case is replaced by a larger bobbin case 34 which includes an internal wax reservoir 36. The bobbin cast 34 includes a central projection 41, over whichthe bobbin 42'slidably fits'so as to be capable of rotation within the bobbin case 34 under withdrawal of the thread.

The b'obbin 42 is prevented from displacement within the bobbin case by a shuttle 44 which is mounted for rotationwithin a shuttle case 50. 'The shuttle 44 ismaintained in position by the shuttle case ring 52 and is .driven in a reciprocal'manner by a cam guided shuttle driver 54, as will be described in more detail later.

The bobbin case 34 is maintainedin non-rotating position relative to the shuttle 44 and bobbin 42 by abobbin case retainer 56. The bobbin case retainer 56 is an integral part of the wax delivery system, including a wax 'deliverytube "58 which extends from a main reservoir 60 mounted on a frame 62. The frame 62 is mounted for "pivotal movement to the shuttle casing 50 by the alignment of a'projecting arm 63 of the frame 62 with a corresponding projecting arm 51 of the casing 50 and by the engagement of a screw-ended bolt 64 with the respective projecting arms. The frame 62is maintained in thedesired alignment relative to the shuttlecasing 50 by .the "engagement of a threaded stud 70' extending from the casing 50 with a corresponding slot 72 provided on a further extended arm portion '65 of the frame 62. A

tapped hold-down nut 74 is engaged with the stud 70 so as to bear against the portion 65 of the frame 62.

The main wax reservoir 60 mounted on the frame 62 is provided with a cap 66 having a central opening 68 and a further offset opening 70. A plunger 72 is adaptedto slidably fit through the opening into the wax delivery tube 58. The wax delivery tube 58 extends within the 4 7 wax reservoir 60 to adjacent the top and is provided with aside opening 74 communicating with the interior of'the Wax reservoir 60. The other end of the wax delivery tube 58 is adjustabiy connected to the upper end of the bobbin case retainer 56. The upper portion of the bobbin case retainer 56 at the point of connection with the tube 58 is provided with an interior wax delivery spout 76 which leads from the tube 58 through a top opening 35 of the bobbin case 34 into the small wax reservoir 36 through which the thread from the bobbin 42 is eventually fed.

The plunger 72 is an extension of the cylindrical mem-; ber 80 which is located for reciprocal vertical movement on top of the reservoir 60, this movement being guided by the slidable engagement of the plunger portion 72 within the tube 58. The member 80 is provided on one side with a toothed rack 82 and on the opposite side of the member an outwardly extending pin 84. Suitable counter weights 86 are secured to the top of the member 86 to provide sufficient force to normally urge .the'plunger '72 downwards in the tube 58 so as to force-wax from the I spout 76 into the small wax container 56.

Also provided 'on the cap 66 area pair of ofi-set guide members'90 which are adapted to co-operate'withjthepin 84 extending from the member 8% disconnecting the wax delivery plunger 72 from operation as will be described in more detail later. 7

The member 80, and consequently the plunger 72,'is raised and allowed to 'fall through the action of a partial toothed gear92 mounted on a shaft 94 supported on an extension 96 of the frame 10 directly behind the shuttle casing St). The shaft 94 is driven through a large toothed gear '98 which is rotated through the intermittent action of a pawl and gear arrangement as shown in Figure 12. Essentially, this arrangement consists of'the pawl lever 100 which is reciprocated'through the action of a central cam 132 driven by the main drive of the machine so that it oscillates as is shown in dotted lines in Figure 12. This oscillating movement of the .lever 100 is transmitted through a first gear 103 and a second gear 104. The movement of the gear 103 is controlled by the pawls 106, 108 so that the intermittent motion of the lever 100 causes a constant rotation in one direction, this rotation being transferred by the gear 104 to the intermediate gear 110 and thence to the large gear 98 driving the shaft 94. The rotation of the shaft 94 also rotates the partial gear 92 which is in meshed engagement with the rack 82 of the member 80 so that the member 80, and consequently the plunger 72, is raised until the toothed portionof the gear 92terminates. The termination ofthe meshed engagement of the toothed portion of the gear 92 with the rack 82 releases the member '80 and by reason of the counter Weights .86 the plunger 72 descends in the tube 58 forcing wax from the reservoir 60'into the reservoir36. The provision of theopening 74 in the tube 58 allows the hot wax from the reservoir'60'to fill the tube 58 through this opening upon the raising of the plunger72 past this opening and as the plunger 72 descends beyond the opening.7'4 it is again sealed on, preventing further wax from being drawn into the tube 58 until a further stroke.

The raising and lowering of the plunger 72 occurs in timed relationship relative to the overall function of the machine through the cam action of the cam 102 so that when sufficient thread has been'withdrawn from the bobbin 42 to sew approximately one and one-half (l /2,) or two (2) pairs of soles, the wax reservoir 36, which has been calculated'to contain sufficient wax for this purpose,

is automatically refilled and fresh hot wax is delivered .72 to anintermediate position'which, if continued, would -furnish additional waxsto the reservoir and perhapsJcause it to overflow, and to prevent'thisicondition aspecialstopping arrangement is provided as follows. A pivotally mounted knock-off lever 120 is mounted to the frame adjacent to the large gear 98 so as to extend across the top of the frame into juxtaposed relationship with the end of the'pin 84 extending from the member 80. The end of this lever 120 in actual contact with the pin 84 is shaped at an angle sothat when the lever 120 is depressed, the pin 84 is urged outwards, swivellingthe rack 82 out of engagement with the gear portion 92. This disengagement of the rack 82 allows the plunger 72 to descend to its lower position without opening the passage 74 and providing more wax through the tube 58. As the member descends, the pin 84 engages withand is guided by the guide member a so that it is again swivelled about, bringing the rack 82 once more in alignment against the guide members 90a, 90b for engagement by the toothed portion of the gear 92. The actuation of the lever is controlled by an elongated rod extending from the head of the machine to adjacent the lower base of the machine where it is connected to a pivotally mounted foot treadle 126. r i

As previously mentioned, the shuttle 44 is rotated and counter-rotated through a shuttle driver 54, which is mounted on a shaft 55 so as to be fixed for rotation with but capable of pivotal movement relative to the shaft 55. The shuttle driver 54 is shaped to have two outstanding end portions 57a, 57b, which are adapted to intermittently engage With corresponding slots 59a, 59b provided in the shuttle 44. The intermittent pivotal motion of the shuttle driver 54 is controlled by the contact of a pair of adjustable pins 47, which are positioned on the rear face of the shuttle driver 54 and bear against the inclined inner wall 49 of the shuttlecasing 50. The inner wall 49 of the casing provides a cam surface so that the shuttle driver 54 is gradually pivoted relative to the shaft 55 during its rotation in one direction so that the end 5715 is engaged in one of the slots 59a, 59b and as it continues to rotate the end 57b is withdrawn and the end 57a engages with the other slot of the shuttle 44. This intermittent pivotal action of the shuttle driver 54 is necessary to provide a clearance for the lower thread as it is pulled up by the needle and left on the looper. When the shuttle 44 ro tates to pick up this loop of lower thread, the loop is carried right over the shuttle 44 to the opposite side where, due to the consequent reverse movement of the shuttle 44, it is dropped off around the upper bobbin thread coming from the lower portion of the bobbin case 34. This looping action is shown in sequence in Figures 15, 16, 17 and 18 of the drawings.

The drive to the shaft 55, and consequently the shuttle driver 54, is made through a gear 130, which is intermittently driven in one or the other rotational direction by a shuttle cam lever 132 pivoted to the head of the machine as indicated at 134 and reciprocated by the action of a cam follower 136 riding in the cam groove 138 of the cam wheel 102.

At is shown in detail in Figure 3, the lower portion of the bobbin casing 34 is shaped to provide a dependent end 35 from which the thread is fed from the interior reservoir 36. The lower end of the casing 35 is tapped and provided with a wiping washer 39 that is held in place by a threaded thread guide 43. With this arrangement, as the thread is drawn from the reservoir 36 by the stitching action of the machine, the surplus wax is wiped oil? by the washer 39 and the thread is delivered from the end of the guide 43 into sewing position. The thread passes directly from the bobbin 42 through the top of the bobbin case 34 and down into and through the wax reservoir 36, tension being maintained on the thread by a spring 45 mounted on the bobbin case 34. 1

A slight modification was also necessary in connection with the portion of the apparatus adapted to support the loop of the lower thread prior to its engage- Jnent by the shuttle 44 and for this purpose an addi- 6 tional supporting plate 136 is secured to the exterior of the bobbin case 50 by screws 138. This merely serves as a support for the looper proper indicated at 140 which operates in the usual manner as is shown in detail in Figures 15, 16, 17 and 18.

As mentioned previously, in order that the wax in the large reservoir 60 and in the bobbin case reservoir 36 be maintained at the correct temperature to keep the wax in the required fluid condition, heating elements 144, 146 are provided which fit into suitable receptacles adjacent to the respective reservoirs. This portion of the structure is well known and, therefore, is not shown in exact detail.

As will be appreciated, by reference to the preceeding description and the accompanying drawings, the present bobbin case and waxing arrangement allows for a considerably greater amount of thread to be initially Wound on to the bobbin 42 than is possible in prior art constructions of this nature. Further, the provision of the bobbin case reservoir allows fresh wax to be applied to this thread in measured quantities so that after each one and one-half (1%) or two (2) pairs of soles, the wax supply is replenished and fresh hot wax is applied to the thread.

As will be appreciated, this arrangement allows the machine to operate for a considerable length of time without stoppage and further eliminates any possibility of stale wax or stale wax thread being used in the locking stitch. The provision of the main reservoir for the wax and the present automatic means of supplying fresh wax from this reservoir to the small reservoir acts in a simple manner to keep the machine in operating condition for a considerable length of time.

I claim:

1. A lock-stitching machine for shoes having, in combination with lock-stitching mechanism including a thread receiving bobbin, two wax reservoirs, one of which is mounted adjacent the thread-receiving bobbin of said machine and the second below said first reservoir, said first reservoir being adapted to intermittently supply wax to said second reservoir and said second wax reservoir being in communication with said thread-receiving bobbin, a wax delivery member extending from said first wax reservoir to said second wax reservoir, and means to intermittently control the delivery of said wax.

2.A lock-stitching machine for shoes comprising a supporting stand, a stitching head mounted on said stand, driving means for said stitching head including a controlling earn; a shuttle casing mounted in said stitching head, a bobbin case mounted on said shuttle casing, a first wax reservoir in said bobbin casing, a second wax reservoir mounted above said bobbin case reservoir, means to heat said first and second reservoirs, and wax delivery means adapted to deliver wax intermittently from said second wax reservoir to said first wax reservoir, said wax deliver means being controlled by said controlling cam.

3. A lock-stitching machine as claimed in claim 2, wherein a thread-receiving bobbin is mounted for rotation within said bobbin casing adjacent to said first wax reservoir.

4. A lock-stitching machine as claimed in claim 2, wherein the wax delivery means from said second Wax reservoir to said first wax reservoir comprises a cylindrical conduit and there is a plunger mounted in said conduit for sliding reciprocal movement, said conduit having a portion extending within and communicating with said second wax reservoir, and actuating means adapted to intermittently raise and drop said plunger connected with said controlling cam.

5. A lock-stitching machine as claimed in claim 2, wherein a shuttle is mounted for rotation within said bobbin casing and there is a shuttle driver adapted to intermittently reciprocate said shuttle, said shuttle driver being controlled by said controlling carn.

g 6. .A lock-stitching machine as claimed in claim 5,

wherein :said shuttle 'driver-is' mounted on a shaft for ltrans-axial .rediprocal movement relative to said shuttle, a'agearg'rnounted on said shaftand .an oscillating rack in engagement with saidgear, said 'rack being in oper- Iative engagement with said controlling cam.

' 7. A lock-stitching machine for shoes comprising in combination, a supporting stand, a stitching head mounted on said stand including a shuttle casing, driving and from said-bobbin through said first wax reservoir to the exterior of said bobbin casing, a second wax reservoir mounted on said sewing head above said first wax reservoir, a wax delivery conduit between said first and secondwax reservoirs, and a wax delivery member adapted to*intermittently deliver wax through said conduit from said second wax reservoir to said first wax reservoir, actuating means connected with said wax delivery member and said controlling cam, whereby the intermittent delivery of said wax is in'timed relationship with the driving of said sewing head and consequent withdrawal of'saicl thread from said bobbin in stitching operation.

8. A lock-stitching machine as claimed in claim 7,

' wherein the wax delivery conduit from said second was reservoir to said first wax reservoir is of cylindrical shape and said wax-delivery member comprises a cylindrical plunger mounted in said conduit for sliding reciprocal movement relative thereto, said plunger including an extension having a toothed rack mounted thereon, and a partial gear in meshed engagement with said toothed rack, said partial gear being mounted on a shaft jour- .nalled above said sewing head, and intermittent driving vmeans between saidshaft and said control cam.

9. A lock-stitching machine as claimed in claim 8, wherein an outstanding arm is provided onsaid plunger til 8 extension, a lever is mounted for-pivotal movement above said sewing head with one end in the path of said arm,

"the :other end of said lever beingpivotally connected to an elongated rod, extending to the base .of said stand, and treadle means on said stand connectedto said lever, a whereby depression of said treadle is adapted through said lever, to pivot said lever armend against'said plunger outstanding arm thereby to pivot said plunger out of engagement with said partial gear.

[0. A lock-stitching machine as claimed in claim 8, wherein said thread bobbin is circular and has a diameter to retain wound on thread sufficient for thestitching of about 40 pairs of shoe soles.

11'. A lock-stitching machine as claimed in claim 7,

wherein a=reciprocating shuttle is mounted on said thread bobbin for partial .rotation relative thereto, a shuttle driver mounted in said shuttle casing behind said reciprocating shuttle,- said shuttle driver being adapted to be reciprocated towards and away from said shuttle by a cam surface provided on'said shuttle casing in engagement with the rear face of said shuttle driver, said shuttle driver being mounted on a shaft for transaxial reciprocal movement relative to said shuttle, a gear mounted on said shaft, and an oscillating rack in engagement with said gear, said rack being in operative engagement with said controlling cam;

12. A lock-stitching machine'for shoes having a supporting stand, a stitching headmounted on said stand, a bobbin case mounted in said stitching head including an internal wax reservoir, a second and larger wax reservoir mounted above said bobbin case reservoir and wax delivery means between said upper and lower waxreservoirs for periodically supplying said lower bobbin case reservoir with wax as said machine is operating; including a wax delivery cylinder'and a plunger operating said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS Whipple Nov 19,, 1901 m Ne 

